Files in this item: 1

On the background of a data set of weekly sales and prices for three brands of coffee, this paper discusses various regression models and their relation to the multiplicative competitive-interaction model (the MCI model, see Cooper 1988, 1993) for market-shares. Emphasis is put on the interpretation of the parameters in relation to models for the total sales based on discrete choice models.
Key words and phrases. MCI model, discrete choice model, market-shares, price elasitcity, regression model.

Discrete choice experiments are widely used in relation to health
care. A stream of recent literature therefore aims at testing the validity
of the underlying preference axioms of completeness and transitivity,
and detecting other preference phenomena such as unstability, learn-
ing/tiredness effects, ordering effects, dominance, etc. Unfortunately
there seems to be some confusion about what is actually being tested,
and the link between the statistical tests performed and the relevant
underlying model of respondent behaviour has not been explored in
this literature. The present paper tries to clarify the notions involved
and discuss what can be tested in a general frequency of choice frame-
work and more specifically in a random utility model.